Common ingredients in weight loss products and dietary supplements

Common Ingredients in Weight Loss products and Dietary Supplements

Ingredient	Proposed Mechanism of Action	Evidence of Efficacy	Evidence of Safety+
Bitter orange (synephrine)	Increases energy expenditure and lipolysis, acts as a mild appetite suppressant	Small clinical trials of poor methodological quality Research findings: Possible effect on resting metabolic rate and energy expenditure; inconclusive effects on weight loss	Some safety concerns reported Reported adverse effects: Chest pain, anxiety, and increased blood pressure and heart rate
Caffeine (as added caffeine or from guarana, kola nut, yerba mate, or other herbs)	Stimulates central nervous system, increases thermogenesis and fat oxidation	Short-term clinical trials of combination products Research findings: Possible modest effect on body weight or decreased weight gain over time	Safety concerns not usually reported at doses less than 400 mg/day for adults, significant safety concerns at higher doses Reported adverse effects: Nervousness, jitteriness, vomiting, and tachycardia
Calcium	Increases lipolysis and fat accumulation, decreases fat absorption	Several large clinical trials Research findings: No effect on body weight, weight loss, or prevention of weight gain based on clinical trials	No safety concerns reported at recommended intakes (1,000–1,200 mg/day for adults) Reported adverse effects: Constipation, kidney stones, and interference with zinc and iron absorption at intakes above 2,000–2,500 mg for adults
Chitosan	Binds dietary fat in the digestive tract	Small clinical trials, mostly of poor methodological quality Research findings: Minimal effect on body weight	Few safety concerns reported, could cause allergic reactions Reported adverse effects: Flatulence, bloating, constipation, indigestion, nausea, and heartburn
Chromium	Increases lean muscle mass; promotes fat loss; and reduces food intake, hunger levels, and fat cravings	Several clinical trials of varying methodological quality Research findings: Minimal effect on body weight and body fat	No safety concerns reported at recommended intakes (25–45 mcg/day for adults) Reported adverse effects: Headache, watery stools, constipation, weakness, vertigo, nausea, vomiting, and urticaria (hives)
Coleus forskohlii(forskolin)	Enhances lipolysis and reduces appetite	Few short-term clinical trials Research findings: No effect on body weight	No safety concerns reported Reported adverse effects: None known
Conjugated linoleic acid	Promotes apoptosis in adipose tissue	Several clinical trials Research findings: Minimal effect on body weight and body fat	Few safety concerns reported Reported adverse effects: Abdominal discomfort and pain, constipation, diarrhea, loose stools, dyspepsia, and (possibly) adverse effects on blood lipid profiles
Ephedra (ma huang, ephedrine)	Stimulates central nervous system, increases thermogenesis, reduces appetite	Several short-term clinical trials of good methodological quality, many of ephedra combined with caffeine Research findings: Modest effect on short-term weight loss	Significant safety concerns reported; banned as a dietary supplement ingredient Reported adverse effects: Anxiety, mood changes, nausea, vomiting, hypertension, palpitation, stroke, seizures, heart attack, and death
Fucoxanthin	Increases energy expenditure and fatty acid oxidation, suppresses adipocyte differentiation and lipid accumulation	Studied only in combination with pomegranate-seed oil in one trial in humans Research findings: Insufficient research to draw firm conclusions	No safety concerns reported but not rigorously studied Reported adverse effects: None known
Garcinia cambogia(hydroxycitric acid)	Inhibits lipogenesis, suppresses food intake	Several short-term clinical trials of varying methodological quality Research findings: Little to no effect on body weight	Few safety concerns reported Reported adverse effects: Headache, nausea, upper respiratory tract symptoms, and gastrointestinal symptoms
Glucomannan	Increases feelings of satiety and fullness, prolongs gastric emptying time	Several clinical trials of varying methodological quality, mostly focused on effects on lipid and blood glucose levels Research findings: Little to no effect on body weight	Significant safety concerns reported with tablet forms, which might cause esophageal obstructions, but few safety concerns with other forms Reported adverse effects: Loose stools, flatulence, diarrhea, constipation, and abdominal discomfort
Green coffee bean extract (Coffea aribica, Coffea canephora, Coffea robusta)	Inhibits fat accumulation, modulates glucose metabolism	Few clinical trials, all of poor methodological quality Research findings: Possible modest effect on body weight	Few safety concerns reported but not rigorously studied; contains caffeine Reported adverse effects: Headache and urinary tract infections
Green tea (Camellia sinensis) and green tea extract	Increases energy expenditure and fat oxidation, reduces lipogenesis and fat absorption	Several clinical trials of good methodological quality on green tea catechins with and without caffeine Research findings: Possible modest effect on body weight	No safety concerns reported when used as a beverage, contains caffeine; some safety concerns reported for green tea extract Reported adverse effects (for green tea extract): Constipation, abdominal discomfort, nausea, increased blood pressure, liver damage
Guar gum	Acts as bulking agent in gut, delays gastric emptying, increases feelings of satiety	Several clinical trials of good methodological quality Research findings: No effect on body weight	Few safety concerns reported with currently available formulations Reported adverse effects: Abdominal pain, flatulence, diarrhea, nausea, and cramps
Hoodia (Hoodia gordonii)	Suppresses appetite, reduces food intake	Very little published research in humans Research findings: No effect on energy intake or body weight based on results from one study	Some safety concerns reported, increases heart rate and blood pressure Reported adverse effects: Headache, dizziness, nausea, and vomiting
Pyruvate	Increases lipolysis and energy expenditure	Few clinical trials of weak methodological quality Research findings: Possible minimal effect on body weight and body fat	Few safety concerns reported Reported adverse effects: Diarrhea, gas, bloating, and (possibly) decreased high-density lipoprotein levels
Raspberry ketone	Alters lipid metabolism	Studied only in combination with other ingredients Research findings: Insufficient research to draw firm conclusions	No safety concerns reported but not rigorously studied Reported adverse effects: None known
White kidney bean (Phaseolus vulgaris)	Interferes with breakdown and absorption of carbohydrates by acting as a "starch blocker"	Few clinical trials, all of poor methodological quality Research findings: Possible modest effect on body fat but no effect on body weight	Few safety concerns reported Reported adverse effects: Headache, soft stools, flatulence, and constipation
Yohimbe (Pausinystalia yohimbe, yohimbine)	Has hyperadrenergic effects	Very little research on yohimbe for weight-loss Research findings: No effect on body weight; insufficient research to draw firm conclusions	Significant safety concerns reported Reported adverse effects: Headache, anxiety, agitation, hypertension, and tachycardia

+Listed in order of severity, with the most severe reported side effects listed last.

source: NIH